1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
4 */
5
6 #include <linux/module.h>
7 #include <linux/interrupt.h>
8 #include <linux/delay.h>
9 #include <linux/platform_device.h>
10 #include <linux/gpio/consumer.h>
11 #include <media/cec-pin.h>
12
13 struct cec_gpio {
14 struct cec_adapter *adap;
15 struct device *dev;
16
17 struct gpio_desc *cec_gpio;
18 int cec_irq;
19 bool cec_is_low;
20 bool cec_have_irq;
21
22 struct gpio_desc *hpd_gpio;
23 int hpd_irq;
24 bool hpd_is_high;
25 ktime_t hpd_ts;
26
27 struct gpio_desc *v5_gpio;
28 int v5_irq;
29 bool v5_is_high;
30 ktime_t v5_ts;
31 };
32
cec_gpio_read(struct cec_adapter * adap)33 static bool cec_gpio_read(struct cec_adapter *adap)
34 {
35 struct cec_gpio *cec = cec_get_drvdata(adap);
36
37 if (cec->cec_is_low)
38 return false;
39 return gpiod_get_value(cec->cec_gpio);
40 }
41
cec_gpio_high(struct cec_adapter * adap)42 static void cec_gpio_high(struct cec_adapter *adap)
43 {
44 struct cec_gpio *cec = cec_get_drvdata(adap);
45
46 if (!cec->cec_is_low)
47 return;
48 cec->cec_is_low = false;
49 gpiod_set_value(cec->cec_gpio, 1);
50 }
51
cec_gpio_low(struct cec_adapter * adap)52 static void cec_gpio_low(struct cec_adapter *adap)
53 {
54 struct cec_gpio *cec = cec_get_drvdata(adap);
55
56 if (cec->cec_is_low)
57 return;
58 if (WARN_ON_ONCE(cec->cec_have_irq))
59 free_irq(cec->cec_irq, cec);
60 cec->cec_have_irq = false;
61 cec->cec_is_low = true;
62 gpiod_set_value(cec->cec_gpio, 0);
63 }
64
cec_hpd_gpio_irq_handler_thread(int irq,void * priv)65 static irqreturn_t cec_hpd_gpio_irq_handler_thread(int irq, void *priv)
66 {
67 struct cec_gpio *cec = priv;
68
69 cec_queue_pin_hpd_event(cec->adap, cec->hpd_is_high, cec->hpd_ts);
70 return IRQ_HANDLED;
71 }
72
cec_5v_gpio_irq_handler(int irq,void * priv)73 static irqreturn_t cec_5v_gpio_irq_handler(int irq, void *priv)
74 {
75 struct cec_gpio *cec = priv;
76 bool is_high = gpiod_get_value(cec->v5_gpio);
77
78 if (is_high == cec->v5_is_high)
79 return IRQ_HANDLED;
80 cec->v5_ts = ktime_get();
81 cec->v5_is_high = is_high;
82 return IRQ_WAKE_THREAD;
83 }
84
cec_5v_gpio_irq_handler_thread(int irq,void * priv)85 static irqreturn_t cec_5v_gpio_irq_handler_thread(int irq, void *priv)
86 {
87 struct cec_gpio *cec = priv;
88
89 cec_queue_pin_5v_event(cec->adap, cec->v5_is_high, cec->v5_ts);
90 return IRQ_HANDLED;
91 }
92
cec_hpd_gpio_irq_handler(int irq,void * priv)93 static irqreturn_t cec_hpd_gpio_irq_handler(int irq, void *priv)
94 {
95 struct cec_gpio *cec = priv;
96 bool is_high = gpiod_get_value(cec->hpd_gpio);
97
98 if (is_high == cec->hpd_is_high)
99 return IRQ_HANDLED;
100 cec->hpd_ts = ktime_get();
101 cec->hpd_is_high = is_high;
102 return IRQ_WAKE_THREAD;
103 }
104
cec_gpio_irq_handler(int irq,void * priv)105 static irqreturn_t cec_gpio_irq_handler(int irq, void *priv)
106 {
107 struct cec_gpio *cec = priv;
108
109 cec_pin_changed(cec->adap, gpiod_get_value(cec->cec_gpio));
110 return IRQ_HANDLED;
111 }
112
cec_gpio_enable_irq(struct cec_adapter * adap)113 static bool cec_gpio_enable_irq(struct cec_adapter *adap)
114 {
115 struct cec_gpio *cec = cec_get_drvdata(adap);
116
117 if (cec->cec_have_irq)
118 return true;
119
120 if (request_irq(cec->cec_irq, cec_gpio_irq_handler,
121 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
122 adap->name, cec))
123 return false;
124 cec->cec_have_irq = true;
125 return true;
126 }
127
cec_gpio_disable_irq(struct cec_adapter * adap)128 static void cec_gpio_disable_irq(struct cec_adapter *adap)
129 {
130 struct cec_gpio *cec = cec_get_drvdata(adap);
131
132 if (cec->cec_have_irq)
133 free_irq(cec->cec_irq, cec);
134 cec->cec_have_irq = false;
135 }
136
cec_gpio_status(struct cec_adapter * adap,struct seq_file * file)137 static void cec_gpio_status(struct cec_adapter *adap, struct seq_file *file)
138 {
139 struct cec_gpio *cec = cec_get_drvdata(adap);
140
141 seq_printf(file, "mode: %s\n", cec->cec_is_low ? "low-drive" : "read");
142 if (cec->cec_have_irq)
143 seq_printf(file, "using irq: %d\n", cec->cec_irq);
144 if (cec->hpd_gpio)
145 seq_printf(file, "hpd: %s\n",
146 cec->hpd_is_high ? "high" : "low");
147 if (cec->v5_gpio)
148 seq_printf(file, "5V: %s\n",
149 cec->v5_is_high ? "high" : "low");
150 }
151
cec_gpio_read_hpd(struct cec_adapter * adap)152 static int cec_gpio_read_hpd(struct cec_adapter *adap)
153 {
154 struct cec_gpio *cec = cec_get_drvdata(adap);
155
156 if (!cec->hpd_gpio)
157 return -ENOTTY;
158 return gpiod_get_value(cec->hpd_gpio);
159 }
160
cec_gpio_read_5v(struct cec_adapter * adap)161 static int cec_gpio_read_5v(struct cec_adapter *adap)
162 {
163 struct cec_gpio *cec = cec_get_drvdata(adap);
164
165 if (!cec->v5_gpio)
166 return -ENOTTY;
167 return gpiod_get_value(cec->v5_gpio);
168 }
169
cec_gpio_free(struct cec_adapter * adap)170 static void cec_gpio_free(struct cec_adapter *adap)
171 {
172 cec_gpio_disable_irq(adap);
173 }
174
175 static const struct cec_pin_ops cec_gpio_pin_ops = {
176 .read = cec_gpio_read,
177 .low = cec_gpio_low,
178 .high = cec_gpio_high,
179 .enable_irq = cec_gpio_enable_irq,
180 .disable_irq = cec_gpio_disable_irq,
181 .status = cec_gpio_status,
182 .free = cec_gpio_free,
183 .read_hpd = cec_gpio_read_hpd,
184 .read_5v = cec_gpio_read_5v,
185 };
186
cec_gpio_probe(struct platform_device * pdev)187 static int cec_gpio_probe(struct platform_device *pdev)
188 {
189 struct device *dev = &pdev->dev;
190 struct cec_gpio *cec;
191 int ret;
192
193 cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
194 if (!cec)
195 return -ENOMEM;
196
197 cec->dev = dev;
198
199 cec->cec_gpio = devm_gpiod_get(dev, "cec", GPIOD_OUT_HIGH_OPEN_DRAIN);
200 if (IS_ERR(cec->cec_gpio))
201 return PTR_ERR(cec->cec_gpio);
202 cec->cec_irq = gpiod_to_irq(cec->cec_gpio);
203
204 cec->hpd_gpio = devm_gpiod_get_optional(dev, "hpd", GPIOD_IN);
205 if (IS_ERR(cec->hpd_gpio))
206 return PTR_ERR(cec->hpd_gpio);
207
208 cec->v5_gpio = devm_gpiod_get_optional(dev, "v5", GPIOD_IN);
209 if (IS_ERR(cec->v5_gpio))
210 return PTR_ERR(cec->v5_gpio);
211
212 cec->adap = cec_pin_allocate_adapter(&cec_gpio_pin_ops,
213 cec, pdev->name, CEC_CAP_DEFAULTS | CEC_CAP_PHYS_ADDR |
214 CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN);
215 if (IS_ERR(cec->adap))
216 return PTR_ERR(cec->adap);
217
218 if (cec->hpd_gpio) {
219 cec->hpd_irq = gpiod_to_irq(cec->hpd_gpio);
220 ret = devm_request_threaded_irq(dev, cec->hpd_irq,
221 cec_hpd_gpio_irq_handler,
222 cec_hpd_gpio_irq_handler_thread,
223 IRQF_ONESHOT |
224 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
225 "hpd-gpio", cec);
226 if (ret)
227 return ret;
228 }
229
230 if (cec->v5_gpio) {
231 cec->v5_irq = gpiod_to_irq(cec->v5_gpio);
232 ret = devm_request_threaded_irq(dev, cec->v5_irq,
233 cec_5v_gpio_irq_handler,
234 cec_5v_gpio_irq_handler_thread,
235 IRQF_ONESHOT |
236 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
237 "v5-gpio", cec);
238 if (ret)
239 return ret;
240 }
241
242 ret = cec_register_adapter(cec->adap, &pdev->dev);
243 if (ret) {
244 cec_delete_adapter(cec->adap);
245 return ret;
246 }
247
248 platform_set_drvdata(pdev, cec);
249 return 0;
250 }
251
cec_gpio_remove(struct platform_device * pdev)252 static int cec_gpio_remove(struct platform_device *pdev)
253 {
254 struct cec_gpio *cec = platform_get_drvdata(pdev);
255
256 cec_unregister_adapter(cec->adap);
257 return 0;
258 }
259
260 static const struct of_device_id cec_gpio_match[] = {
261 {
262 .compatible = "cec-gpio",
263 },
264 {},
265 };
266 MODULE_DEVICE_TABLE(of, cec_gpio_match);
267
268 static struct platform_driver cec_gpio_pdrv = {
269 .probe = cec_gpio_probe,
270 .remove = cec_gpio_remove,
271 .driver = {
272 .name = "cec-gpio",
273 .of_match_table = cec_gpio_match,
274 },
275 };
276
277 module_platform_driver(cec_gpio_pdrv);
278
279 MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
280 MODULE_LICENSE("GPL v2");
281 MODULE_DESCRIPTION("CEC GPIO driver");
282
